Diesel Exhaust Fluid (“DEF”) helps meet EPA 2010 NOx emissions standards. Most large diesel engine vehicles manufactured since 2010 utilize Selective Catalytic Reduction (SCR) requiring DEF injected into the exhaust stream to reduce NOx emissions in the engine's exhaust. Unlike diesel fuel, DEF freezes at approximately 12° Fahrenheit. When DEF freezes, it can expand up to 7%. When disposed within a container or tank, such as a flow meter, expansion of the DEF can result in significant damage.
Freeze plugs or expansion plugs are often used in the engine block of a car to prevent damage when water or coolant freezes. A freeze plug is a round plug that is pressed into a hole formed in the engine block and it is designed to “pop out” to allow for expansion of the water upon freezing. However, there are several problems with current freeze plugs: they can introduce additional leak points, and they often fail to “pop out.” Additionally, traditional freeze plugs are not designed for use when the system is in operation. Therefore, once a freeze plug has “popped out,” the system must receive maintenance before it can be placed back in service. For these reasons, it is not practical or reasonable to use a traditional freeze plug in a fuel dispenser.
Accordingly, there remains a need for improved methods and devices for preventing cracking of a fluid-filled chamber.